/* "eye" sensors return 1 if above light, 0 if above dark *//* try to keep left on light, right on dark */  while (1)  {  /* if left eye sees black, turn left */  if (left_eye() == 0) veer_left();  /* if right eye sees white, turn right */  else if (right_eye() == 1) veer_right();    /* otherwise, go straight */  else forward();    /* check for touch sensors */  if (left_touch() || right_touch()) break;}